Why Does My Guitar Buzz or Rattle? – Spot Leveling High Frets

Why does your guitar buzz on certain notes? Incorrect setup or one high fret may be responsible. Learn how a fret rocker identifies the problem and how localized fret leveling, polishing and fretboard care can help.

Why does my guitar buzz or rattle?

If a guitar buzzes or rattles, there can be several causes. The string action may be too low, the neck relief may be incorrect, or one or more frets may sit slightly higher than their neighbors. It is important to diagnose the cause rather than simply raising the strings.

Start with the guitar setup

A guitar with very low action or unsuitable neck relief can buzz even when the frets are perfectly level. Read our articles on adjusting guitar string action and intonation and understanding neck relief and truss rod adjustment.

If the guitar still buzzes on particular notes after its setup has been checked, a locally high fret may be the cause.

Finding a high fret with a fret rocker

In the workshop, I use a short precision straightedge known as a fret rocker. It rests across three frets at a time. If it rocks, this can indicate that the middle fret is higher than its neighbors. By checking different positions across the fingerboard, the problem area can be identified.

Spot leveling – remove only what is necessary

When just one fret is too high, leveling every fret is not always necessary. Spot leveling treats only the affected area. The high fret is carefully filed down to match the neighboring frets. Its rounded crown is then restored to give the string a precise contact point.

Polishing the frets

After filing, the fret is smoothed and polished to remove tool marks. A smooth fret surface improves playing feel and makes string bending more comfortable.

Cleaning and oiling the fingerboard

Finally, the fingerboard is cleaned. If the wood and finish are suitable, a small amount of appropriate fingerboard oil may be applied, and any excess wiped away. Finished or lacquered fingerboards generally should not be oiled in the same way.

A buzzing guitar does not always need a complete fret level. Once the cause has been identified, careful localized work may be enough to restore clean, even playability.